Cut part of a video, crop it and blackout parts of it

Previous Topic Next Topic
 
classic Classic list List threaded Threaded
12 messages Options
Reply | Threaded
Open this post in threaded view
|

Cut part of a video, crop it and blackout parts of it

FFmpeg-users mailing list
I have to cut out a part of a video, crop it and blackout two parts.
I do this with:
    ffmpeg -y                                      \
           -ss 00:19:49                            \
           -i  2021-03-25ToastmastersClubAvond.mp4 \
           -to 442                                 \
           -vf "
                crop = 1440:1080:240:0
                ,
                drawbox=enable='between(t, 0, 2)'     :
                   color     = black                  :
                   w         = in_w                   :
                   h         = in_h                   :
                   thickness = fill
                ,
                drawbox=enable='between(t, 339, 342)' :
                   color     = black                  :
                   w         = in_w                   :
                   h         = in_h                   :
                   thickness = fill
           "                                       \
           -acodec copy                            \
           -vcodec libx264                         \
           -crf    23                              \
           speechClean2.mp4

The reason I do -to in the output is that in this way the metadata
concerning the video length is less out of whack.

I was wondering if this is a good way, or that it could be done
better?
Also, beside the timestamps the parameters for drawbox are the same.
Is there a way that I do not have to repeat them?

I started the crf with 16, then 20 and lastly 23.

The input file has:
    Stream #0:1(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080, 2070 kb/s, 25 fps, 25 tbr, 30k tbn, 60k tbc (default)

With crf 16 I get:
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1440x1080, 5541 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)

With crf 20 I get:
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1440x1080, 3538 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)

And with crf 23 I get:
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1440x1080, 2444 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)

So to me it seems that the crf value is still to high. Is there a way
to use the kb/s to calculate the crf value to use?

--
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: Cut part of a video, crop it and blackout parts of it

Carl Eugen Hoyos-2


> Am 05.04.2021 um 01:48 schrieb Cecil Westerhof via ffmpeg-user <[hidden email]>:
>
> I have to cut out a part of a video, crop it and blackout two parts.
> I do this with:
>    ffmpeg -y                                      \
>           -ss 00:19:49                            \
>           -i  2021-03-25ToastmastersClubAvond.mp4 \
>           -to 442                                 \
>           -vf "
>                crop = 1440:1080:240:0
>                ,
>                drawbox=enable='between(t, 0, 2)'     :
>                   color     = black                  :
>                   w         = in_w                   :
>                   h         = in_h                   :
>                   thickness = fill
>                ,
>                drawbox=enable='between(t, 339, 342)' :
>                   color     = black                  :
>                   w         = in_w                   :
>                   h         = in_h                   :
>                   thickness = fill
>           "                                       \
>           -acodec copy                            \
>           -vcodec libx264                         \
>           -crf    23                              \
>           speechClean2.mp4
>
> The reason I do -to in the output is that in this way the metadata
> concerning the video length is less out of whack.
>
> I was wondering if this is a good way, or that it could be done
> better?

> Also, beside the timestamps the parameters for drawbox are the same.
> Is there a way that I do not have to repeat them?

I suspect there is an „Or“ parameter for „enable“.

>
> I started the crf with 16, then 20 and lastly 23.
>
> The input file has:
>    Stream #0:1(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080, 2070 kb/s, 25 fps, 25 tbr, 30k tbn, 60k tbc (default)
>
> With crf 16 I get:
>    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1440x1080, 5541 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
>
> With crf 20 I get:
>    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1440x1080, 3538 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
>
> And with crf 23 I get:
>    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1440x1080, 2444 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
>
> So to me it seems that the crf value is still to high.

You mean still too low?

> Is there a way
> to use the kb/s to calculate the crf value to use?

There is a fundamental misunderstanding:
You decide how much quality you want to preserve, x264 decides how much bitrate is needed to reach that quality. (This is true for the general case where you want to control the output quality and are therefore using the crf option.)
If you really have bitrate constraints, use two-pass encoding instead of the crf option.

I suspect the reason for the high bitrate of the output file is the low quality of the input file but this is not really relevant, just a (possible) explanation. One (unlikely) alternative is that your original h264 encoder is much better than x264.

Carl Eugen
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: Cut part of a video, crop it and blackout parts of it

Michael Koch
In reply to this post by FFmpeg-users mailing list
Am 05.04.2021 um 01:48 schrieb Cecil Westerhof via ffmpeg-user:

> I have to cut out a part of a video, crop it and blackout two parts.
> I do this with:
>      ffmpeg -y                                      \
>             -ss 00:19:49                            \
>             -i  2021-03-25ToastmastersClubAvond.mp4 \
>             -to 442                                 \
>             -vf "
>                  crop = 1440:1080:240:0
>                  ,
>                  drawbox=enable='between(t, 0, 2)'     :
>                     color     = black                  :
>                     w         = in_w                   :
>                     h         = in_h                   :
>                     thickness = fill
>                  ,
>                  drawbox=enable='between(t, 339, 342)' :
>                     color     = black                  :
>                     w         = in_w                   :
>                     h         = in_h                   :
>                     thickness = fill
>             "                                       \
>             -acodec copy                            \
>             -vcodec libx264                         \
>             -crf    23                              \
>             speechClean2.mp4
>
> The reason I do -to in the output is that in this way the metadata
> concerning the video length is less out of whack.
>
> I was wondering if this is a good way, or that it could be done
> better?
> Also, beside the timestamps the parameters for drawbox are the same.
> Is there a way that I do not have to repeat them?

drawbox=enable='bitor(between(t, 0, 2),between(t, 339, 342))'

Michael

_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: Cut part of a video, crop it and blackout parts of it

Nicolas George
In reply to this post by Carl Eugen Hoyos-2
Carl Eugen Hoyos (12021-04-05):
> There is a fundamental misunderstanding:
> You decide how much quality you want to preserve, x264 decides how
> much bitrate is needed to reach that quality.

You also decide how much computing power you want to spend on it, which
Cecil neglected to do. More computing power usually means lower bitrate
for same quality. The keyword is "preset".

Regards,

--
  Nicolas George

_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".

signature.asc (849 bytes) Download Attachment
Reply | Threaded
Open this post in threaded view
|

Re: Cut part of a video, crop it and blackout parts of it

FFmpeg-users mailing list
In reply to this post by Carl Eugen Hoyos-2
Carl Eugen Hoyos <[hidden email]> writes:

>> Am 05.04.2021 um 01:48 schrieb Cecil Westerhof via ffmpeg-user <[hidden email]>:
>>
>> I have to cut out a part of a video, crop it and blackout two parts.
>> I do this with:
>>    ffmpeg -y                                      \
>>           -ss 00:19:49                            \
>>           -i  2021-03-25ToastmastersClubAvond.mp4 \
>>           -to 442                                 \
>>           -vf "
>>                crop = 1440:1080:240:0
>>                ,
>>                drawbox=enable='between(t, 0, 2)'     :
>>                   color     = black                  :
>>                   w         = in_w                   :
>>                   h         = in_h                   :
>>                   thickness = fill
>>                ,
>>                drawbox=enable='between(t, 339, 342)' :
>>                   color     = black                  :
>>                   w         = in_w                   :
>>                   h         = in_h                   :
>>                   thickness = fill
>>           "                                       \
>>           -acodec copy                            \
>>           -vcodec libx264                         \
>>           -crf    23                              \
>>           speechClean2.mp4
>>
>> The reason I do -to in the output is that in this way the metadata
>> concerning the video length is less out of whack.
>>
>> I was wondering if this is a good way, or that it could be done
>> better?
>
>> Also, beside the timestamps the parameters for drawbox are the same.
>> Is there a way that I do not have to repeat them?
>
> I suspect there is an „Or“ parameter for „enable“.
>
>>
>> I started the crf with 16, then 20 and lastly 23.
>>
>> The input file has:
>>    Stream #0:1(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p,
>> 1920x1080, 2070 kb/s, 25 fps, 25 tbr, 30k tbn, 60k tbc (default)
>>
>> With crf 16 I get:
>>    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p,
>> 1440x1080, 5541 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
>>
>> With crf 20 I get:
>>    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p,
>> 1440x1080, 3538 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
>>
>> And with crf 23 I get:
>>    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p,
>> 1440x1080, 2444 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
>>
>> So to me it seems that the crf value is still to high.
>
> You mean still too low?

Yes, bitrate is to high, so the crf value is to low. Silly me. ;-)


>> Is there a way
>> to use the kb/s to calculate the crf value to use?
>
> There is a fundamental misunderstanding:
> You decide how much quality you want to preserve, x264 decides how much
> bitrate is needed to reach that quality. (This is true for the general
> case where you want to control the output quality and are therefore
> using the crf option.)
> If you really have bitrate constraints, use two-pass encoding
> instead of the crf option.

I do not really have a bitrate constraint, but I would think a higher
bitrate as the input bitrate would be a waste. Because the crop
removes about a quarter I would think that a bitrate higher as 1500
would be a waste.


> I suspect the reason for the high bitrate of the output file is the low
> quality of the input file but this is not really relevant, just a
> (possible) explanation. One (unlikely) alternative is that your original
> h264 encoder is much better than x264.

That is what I mean: if the quality of the input is low, then there is
no use for going for a high(er) quality for the output.

--
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: Cut part of a video, crop it and blackout parts of it

FFmpeg-users mailing list
In reply to this post by Nicolas George
Nicolas George <[hidden email]> writes:

> Carl Eugen Hoyos (12021-04-05):
>> There is a fundamental misunderstanding:
>> You decide how much quality you want to preserve, x264 decides how
>> much bitrate is needed to reach that quality.
>
> You also decide how much computing power you want to spend on it, which
> Cecil neglected to do. More computing power usually means lower bitrate
> for same quality. The keyword is "preset".

Yes, that was not smart.

The funny thing about that is that years ago I have played with that.
My very strange finding was that I could best use veryfast. It was
faster and created smaller files. But that is many years ago, so maybe
that is not true anymore.

Time to play with preset again.

--
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: Cut part of a video, crop it and blackout parts of it

FFmpeg-users mailing list
In reply to this post by Michael Koch
Michael Koch <[hidden email]> writes:

> Am 05.04.2021 um 01:48 schrieb Cecil Westerhof via ffmpeg-user:
>> I have to cut out a part of a video, crop it and blackout two parts.
>> I do this with:
>>      ffmpeg -y                                      \
>>             -ss 00:19:49                            \
>>             -i  2021-03-25ToastmastersClubAvond.mp4 \
>>             -to 442                                 \
>>             -vf "
>>                  crop = 1440:1080:240:0
>>                  ,
>>                  drawbox=enable='between(t, 0, 2)'     :
>>                     color     = black                  :
>>                     w         = in_w                   :
>>                     h         = in_h                   :
>>                     thickness = fill
>>                  ,
>>                  drawbox=enable='between(t, 339, 342)' :
>>                     color     = black                  :
>>                     w         = in_w                   :
>>                     h         = in_h                   :
>>                     thickness = fill
>>             "                                       \
>>             -acodec copy                            \
>>             -vcodec libx264                         \
>>             -crf    23                              \
>>             speechClean2.mp4
>>
>> The reason I do -to in the output is that in this way the metadata
>> concerning the video length is less out of whack.
>>
>> I was wondering if this is a good way, or that it could be done
>> better?
>> Also, beside the timestamps the parameters for drawbox are the same.
>> Is there a way that I do not have to repeat them?
>
> drawbox=enable='bitor(between(t, 0, 2),between(t, 339, 342))'

Works like a charm.

Strange thing is that it seems to be much faster. About 20%. To much
to be because of different load I think.
But I am not complaining. ;-)

--
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: Cut part of a video, crop it and blackout parts of it

FFmpeg-users mailing list
In reply to this post by FFmpeg-users mailing list
Cecil Westerhof via ffmpeg-user <[hidden email]> writes:

> Nicolas George <[hidden email]> writes:
>
>> Carl Eugen Hoyos (12021-04-05):
>>> There is a fundamental misunderstanding:
>>> You decide how much quality you want to preserve, x264 decides how
>>> much bitrate is needed to reach that quality.
>>
>> You also decide how much computing power you want to spend on it, which
>> Cecil neglected to do. More computing power usually means lower bitrate
>> for same quality. The keyword is "preset".
>
> Yes, that was not smart.
>
> The funny thing about that is that years ago I have played with that.
> My very strange finding was that I could best use veryfast. It was
> faster and created smaller files. But that is many years ago, so maybe
> that is not true anymore.

Until two years ago it was still the case:
    https://write.corbpie.com/ffmpeg-preset-comparison-x264-2019-encode-speed-and-file-size/

I ran it with veryfast. It took about half the time and kb/s was 2164
instead of 2444. Better, but still about 40% higher as I would expect.

--
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: Cut part of a video, crop it and blackout parts of it

Michael Koch
In reply to this post by FFmpeg-users mailing list
Am 05.04.2021 um 11:58 schrieb Cecil Westerhof via ffmpeg-user:

> Michael Koch <[hidden email]> writes:
>
>> Am 05.04.2021 um 01:48 schrieb Cecil Westerhof via ffmpeg-user:
>>> I have to cut out a part of a video, crop it and blackout two parts.
>>> I do this with:
>>>       ffmpeg -y                                      \
>>>              -ss 00:19:49                            \
>>>              -i  2021-03-25ToastmastersClubAvond.mp4 \
>>>              -to 442                                 \
>>>              -vf "
>>>                   crop = 1440:1080:240:0
>>>                   ,
>>>                   drawbox=enable='between(t, 0, 2)'     :
>>>                      color     = black                  :
>>>                      w         = in_w                   :
>>>                      h         = in_h                   :
>>>                      thickness = fill
>>>                   ,
>>>                   drawbox=enable='between(t, 339, 342)' :
>>>                      color     = black                  :
>>>                      w         = in_w                   :
>>>                      h         = in_h                   :
>>>                      thickness = fill
>>>              "                                       \
>>>              -acodec copy                            \
>>>              -vcodec libx264                         \
>>>              -crf    23                              \
>>>              speechClean2.mp4
>>>
>>> The reason I do -to in the output is that in this way the metadata
>>> concerning the video length is less out of whack.
>>>
>>> I was wondering if this is a good way, or that it could be done
>>> better?
>>> Also, beside the timestamps the parameters for drawbox are the same.
>>> Is there a way that I do not have to repeat them?
>> drawbox=enable='bitor(between(t, 0, 2),between(t, 339, 342))'
> Works like a charm.
>
> Strange thing is that it seems to be much faster. About 20%. To much
> to be because of different load I think.
> But I am not complaining. ;-)

If you want to cover the whole frame size, you could also use this (for
50% gray):
eq=enable='bitor(between(t, 0, 2),between(t, 339, 342))':contrast=0
or add :brightness=-0.5 if you want black.
It might be faster than drawbox.

Michael

_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: Cut part of a video, crop it and blackout parts of it

FFmpeg-users mailing list
In reply to this post by FFmpeg-users mailing list
Cecil Westerhof via ffmpeg-user <[hidden email]> writes:

> I have to cut out a part of a video, crop it and blackout two parts.
> I do this with:
>     ffmpeg -y                                      \
>            -ss 00:19:49                            \
>            -i  2021-03-25ToastmastersClubAvond.mp4 \
>            -to 442                                 \
>            -vf "
>                 crop = 1440:1080:240:0
>                 ,
>                 drawbox=enable='between(t, 0, 2)'     :
>                    color     = black                  :
>                    w         = in_w                   :
>                    h         = in_h                   :
>                    thickness = fill
>                 ,
>                 drawbox=enable='between(t, 339, 342)' :
>                    color     = black                  :
>                    w         = in_w                   :
>                    h         = in_h                   :
>                    thickness = fill
>            "                                       \
>            -acodec copy                            \
>            -vcodec libx264                         \
>            -crf    23                              \
>            speechClean2.mp4

With the help of this mailing list I changed it to:
    ffmpeg -y                                      \
           -ss 00:19:49                            \
           -i  2021-03-25ToastmastersClubAvond.mp4 \
           -to 442                                 \
           -vf "
                crop = 1440:1080:240:0
                ,
                drawbox=enable='bitor(between(t, 0, 2),between(t, 339, 342))' :
                   color     = black                                          :
                   w         = in_w                                           :
                   h         = in_h                                           :
                   thickness = fill
           "                                       \
           -acodec copy                            \
           -vcodec libx264                         \
           -preset veryfast                        \
           -crf    28                              \
           speechClean3.mp4

The input quality is probably poor, that is why I switched to crf 28.
I do not see a difference in quality.

I use veryfast because that probably gives (counter-intuitively) the
smallest size.


> The reason I do -to in the output is that in this way the metadata
> concerning the video length is less out of whack.
>
> I was wondering if this is a good way, or that it could be done
> better?
> Also, beside the timestamps the parameters for drawbox are the same.
> Is there a way that I do not have to repeat them?
>
> I started the crf with 16, then 20 and lastly 23.
>
> The input file has:
>     Stream #0:1(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080, 2070 kb/s, 25 fps, 25 tbr, 30k tbn, 60k tbc (default)
>
> With crf 16 I get:
>     Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1440x1080, 5541 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
>
> With crf 20 I get:
>     Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1440x1080, 3538 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
>
> And with crf 23 I get:
>     Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1440x1080, 2444 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)

With crf 28 and preset veryfast I get:
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1440x1080, 1056 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)


When I have better quality video I should maybe change crf back to 23.

--
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: Cut part of a video, crop it and blackout parts of it

FFmpeg-users mailing list
In reply to this post by Michael Koch
Michael Koch <[hidden email]> writes:

> Am 05.04.2021 um 11:58 schrieb Cecil Westerhof via ffmpeg-user:
>> Michael Koch <[hidden email]> writes:
>>
>>> Am 05.04.2021 um 01:48 schrieb Cecil Westerhof via ffmpeg-user:
>>>> I have to cut out a part of a video, crop it and blackout two parts.
>>>> I do this with:
>>>>       ffmpeg -y                                      \
>>>>              -ss 00:19:49                            \
>>>>              -i  2021-03-25ToastmastersClubAvond.mp4 \
>>>>              -to 442                                 \
>>>>              -vf "
>>>>                   crop = 1440:1080:240:0
>>>>                   ,
>>>>                   drawbox=enable='between(t, 0, 2)'     :
>>>>                      color     = black                  :
>>>>                      w         = in_w                   :
>>>>                      h         = in_h                   :
>>>>                      thickness = fill
>>>>                   ,
>>>>                   drawbox=enable='between(t, 339, 342)' :
>>>>                      color     = black                  :
>>>>                      w         = in_w                   :
>>>>                      h         = in_h                   :
>>>>                      thickness = fill
>>>>              "                                       \
>>>>              -acodec copy                            \
>>>>              -vcodec libx264                         \
>>>>              -crf    23                              \
>>>>              speechClean2.mp4
>>>>
>>>> The reason I do -to in the output is that in this way the metadata
>>>> concerning the video length is less out of whack.
>>>>
>>>> I was wondering if this is a good way, or that it could be done
>>>> better?
>>>> Also, beside the timestamps the parameters for drawbox are the same.
>>>> Is there a way that I do not have to repeat them?
>>> drawbox=enable='bitor(between(t, 0, 2),between(t, 339, 342))'
>> Works like a charm.
>>
>> Strange thing is that it seems to be much faster. About 20%. To much
>> to be because of different load I think.
>> But I am not complaining. ;-)
>
> If you want to cover the whole frame size, you could also use this (for
> 50% gray):
> eq=enable='bitor(between(t, 0, 2),between(t, 339, 342))':contrast=0
> or add :brightness=-0.5 if you want black.
> It might be faster than drawbox.

I will try that out later. At the moment I am working with the
different preset values. It seems that veryfast is still the best. And
that you really should not use ultrafast.

--
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".
Reply | Threaded
Open this post in threaded view
|

Re: Cut part of a video, crop it and blackout parts of it

FFmpeg-users mailing list
In reply to this post by Michael Koch
Michael Koch <[hidden email]> writes:

> If you want to cover the whole frame size, you could also use this (for
> 50% gray):
> eq=enable='bitor(between(t, 0, 2),between(t, 339, 342))':contrast=0
> or add :brightness=-0.5 if you want black.
> It might be faster than drawbox.

It is not faster. It also keeps a 'shadow' of the video. I will play a
little more with it, but the change is high that I go back to drawbox.

--
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof
_______________________________________________
ffmpeg-user mailing list
[hidden email]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[hidden email] with subject "unsubscribe".